Most airlines allow fully-trained service dogs to ride in the cabin without a carrier. Airlines are no longer required to accommodate emotional support animals (ESAs) and they must travel as pets.
What are the TSA rules for dogs?
All pets should be brought to a security checkpoint in a hand-held travel carrier. Remove the pet from the carrier just prior to the beginning of the screening process. Place the empty travel carrier on the checkpoint conveyor belt so it can be X-rayed. Never place a pet in the X-ray tunnel.
How do you fly a large dog not in cargo?
So long as your dog is crated, many airlines, such as Alaskan or American Airlines, allow large dogs to be checked baggage. As the pet owner, you will bring your dog to check in as you would normally with your other bags, and then they will be weighed and moved like the rest of your bags.